Intensely folded and fault-bounded sequence of dark-gray to black, massive to thin-bedded marine flysch-like rocks in the Healy and Mount McKinley quadrangles and including conglomerate, sandstone, siltstone, and argillite, a few thin interbeds of limestone, and thin interbeds of chert in the upper part of unit (Csejtey and others, 1992). Age based on Triassic Radiolaria and conodonts from chert and calcareous units and on a reported collection of Pennsylvanian brachiopods (see Csejtey and others, 1992, p. 28). Unit is thought to be at least several hundred meters thick. Overlain by and locally interbedded with Late Triassic pillow basalt (unit JTrv). Csejtey and others (1992) did not assign either this unit or the basalt to known packages or assemblages because of the discontinuous and fault-bounded nature of their occurrence